Fuel control system and associated method

ABSTRACT

A fuel control system and method for providing fuel to an internal combustion engine are provided. The fuel control system generally includes at least one valve device structured to deliver a fuel supply to the engine, a first fuel source structured to provide a primary fuel to the valve device, a second fuel source structured to provide an alternate fuel to the valve device, and an electronic controller structured to control the valve device. The electronic controller controls the valve device as a function of various data to selectively deliver the primary fuel and the alternate fuel to generate a fuel supply, e.g. as a mixture of the two fuels. The data used to control the fuel supply may include GPS data, engine data, environmental data, and/or other operational data.

BACKGROUND OF THE INVENTION

1) Field of the Invention

The present invention relates to fuel systems for internal combustionengines and more particularly to fuel systems that provide both primaryfuel and alternate fuel to an internal combustion engine.

2) Description of Related Art

For a variety of reasons, most of which relate to environmental andalternative energy pursuits, certain primary fuel engines, such asdiesel engines, can be made to accommodate alternate fuels, such asstraight vegetable oil (SVO), “biodiesel,” and other fuel oils(hereinafter “alternate fuels”). However, practical applications havedemonstrated that full-time use of these alternate fuels is notdesirable. For instance, at low temperatures the viscosity of some ofthese alternate fuels is not optimal for use in an engine designed torun on primary fuel. The alternate fuel should be heated up to atemperature that will allow it to easily pass through the fuel deliverysystem. If left in an idle engine to cool, the alternate fuel also has atendency to increase in viscosity and thus congeal inside the fueldelivery components. Thus, the alternate fuel should not be used untilit has reached an appropriate temperature and it should be purged fromthe engine before shutting down. As a result, some of these systemstypically run on diesel fuel during start-up and before shut down, andrely on the consumer to manually switch to the alternate fuel source inbetween, i.e., when the alternate fuel is at an optimal temperature. Forexample, in an automobile that has been modified to include diesel andalternative fuel tanks, a driver can selectively toggle between the twofuels during operation of the vehicle using a switch that controls theflow of the two fuels.

Recently, some aftermarket automated control systems have been designed.These systems control the switching between a diesel fuel source and analternative fuel source based on the temperature of the alternate fuel.Typically, when the engine is cold, such as during engine start, theengine operates using primary fuel, and once a predetermined alternatefuel temperature or a certain vehicle speed is achieved, the engine isthen switched to the alternate fuel. If low temperature operationreoccurs, the engine is then switched back to primary fuel, and so on.

To automate this fuel selection process, various conventionalaftermarket control systems have been designed that acquire and monitoralternate fuel temperature by using various measurement devices, such astemperature sensors. However, these aftermarket systems are constrainedin that they relate switching between the two fuel sources baseddirectly on the temperature of the alternate fuel. Furthermore,conventional control systems that switch between primary fuel andalternate fuel use either 100% primary fuel or 100% alternate fuel atall times, even though neither fuel may be optimal during some operatingconditions. This abrupt switching of fuels can result in abrupt changesin engine behavior. Reduced or unacceptable performance may beexperienced at or near the switching transition point, and potentialutilization of alternate fuel may be forfeited during intermediateconditions by forcing premature switching of fuel to mitigate transitionbehavior. As a result, conventional alternate fuel systems typicallysuffer from difficulty in integration, do not accommodate grade loading,exhibit poor performance at fuel type transition points, mustunderutilize alternate fuel, and are not applicable to engine typesintolerable of 100% alternate fuel mixtures.

Therefore, an improved system and method of automatically supplying aninternal combustion engine with a primary fuel, an alternate fuel, or acombination of both, based on a variety of operating conditions aredesired.

BRIEF SUMMARY OF THE INVENTION

The present invention provides a fuel control system for controlling theuse of a primary fuel and an alternate fuel in an internal combustionengine. In one embodiment, the present invention comprises at least onevalve device structured to deliver a fuel supply to the engine, a firstfuel source structured to provide a primary fuel to the valve device, asecond fuel source structured to provide an alternate fuel to the valvedevice, an electronic controller structured to control the valve device,and a global positioning system (GPS) receiver configured to transmitGPS data to the electronic controller, wherein the electronic controllercontrols the valve device according to the GPS data to selectivelydeliver the primary fuel and the alternate fuel to generate the fuelsupply. The fuel control system may also deliver a mixture of theprimary fuel and the alternate fuel to generate the fuel supply.

The GPS data may include vehicle speed, vehicle altitude, and groundsurface grade. The primary fuel may comprise one of a diesel fuel or abio-diesel fuel and the alternate fuel may comprise one of a vegetableoil fuel or a bio-diesel fuel. The system may also include a datathreshold value, wherein the electronic controller controls the valvedevice to use mainly primary fuel below the data threshold value, andthe electronic controller controls the valve device to use mainlyalternate fuel above the data threshold value.

The fuel control system may also include a primary valve device thatreceives the primary fuel from the first fuel source and an alternatevalue device that receives alternate fuel from the second fuel source,wherein the electronic controller controls the primary valve deviceaccording to the GPS data to selectively deliver the primary fuel, andthe electronic controller controls the alternate valve device accordingto the GPS data to selectively deliver the alternate fuel, and wherein amixture of the primary fuel delivered by the primary valve device andthe alternate fuel used by the alternate valve device generates the fuelsupply.

The fuel control system may also include at least one of a heatingmechanism structured to heat the alternate fuel, a temperature sensingdevice structured to sense the temperature of the alternate fuel, analternate fuel volume measurement device structured to measure thevolume of the alternate fuel in the second fuel source, and a primaryfuel volume measurement device structured to measure volume of thealternate fuel in the first fuel source. In another aspect, theelectronic controller may receive engine data from the engine, whereinthe electronic controller controls the valve device according to atleast one of the GPS data and the engine data to selectively deliver theprimary fuel and the alternate fuel to generate the fuel supply. Theengine data may comprise at least one of engine RPM data, fuel injectiontiming data, engine exhaust temperature data, engine exhaust particulatedata, engine throttle position data, transmission status data, emissioncontrol system data, ignition status data, and user preferences.

In another embodiment, the present invention provides a fuel controlsystem that includes at least one valve device structured to deliver afuel supply to the engine, a first fuel source structured to provide aprimary fuel to the valve device, a second fuel source structured toprovide an alternate fuel to the valve device, and an electroniccontroller structured to receive operational data and to control thevalve device, wherein the electronic controller controls the valvedevice according to the operational data to selectively deliver theprimary fuel and the alternate fuel to generate the fuel supply. In oneaspect, the electronic controller may control the valve device todeliver a mixture of the primary fuel and the alternate fuel accordingto the operational data. In another aspect, the operational data maycomprise at least one of the speed of the vehicle, engine RPM data, fuelinjection timing data, engine exhaust temperature data, engine exhaustparticulate data, engine throttle position data, transmission statusdata, emission control system data, altitude data, ground grade data,diesel fuel volume data, vegetable fuel volume data, vegetable fueltemperature data, and user preference data.

The fuel control system may include at least one of a primary fuel flowmeasurement device structured to measure a primary fuel flow rate, analternate fuel flow measurement device structured to measure analternate fuel flow rate, and a fuel supply flow measurement devicestructured to measure a fuel supply flow rate. The flow measurementdevices may provide flow rate data to the electronic controller, and theelectronic controller may provide an indication of the amount of use ofthe alternate fuel.

In another embodiment, the valve device may comprise at least one fuelinjector structured to deliver fuel to a combustion chamber of theengine. The at least one fuel injector may be structured to deliver amixture of fuel to the combustion chamber of the engine. The fuelinjector may comprise a first fuel injector that receives the primaryfuel from the first fuel source, and a second fuel injector thatreceives the alternate fuel from the second fuel source. The first fuelinjector may deliver a stream of primary fuel to the combustion chamberof the engine and said second fuel injector may deliver a stream ofalternate fuel to the combustion chamber of the engine. The first fuelinjector may be controlled according to a first fuel injector outputpulse and the second fuel injector may be controlled according to asecond fuel injector output pulse, wherein an original fuel injectortiming pulse is divided to create the first and second fuel injectoroutput pulses. The fuel injectors may be gated sequentially whereineither fuel injector may be gated before the other. The fuel injectorsmay also be gated non-sequentially. Delays may also be introduced.

In another embodiment, the present invention provides a method ofcontrollably delivering fuel to an internal combustion engine of avehicle that comprises transmitting operational data to an electroniccontroller, and controlling at least one valve device with theelectronic controller to selectively deliver at least one of a primaryfuel, an alternate fuel, or a mixture of the primary fuel and thealternate fuel to the engine according to the operational data. The stepof controlling the at least one valve device may also comprisecontrolling a first valve device and a second valve device to deliver atleast one of the primary fuel, the alternate fuel, or a mixture of theprimary fuel and the alternate fuel to the engine according to theoperational data.

Thus, the fuel control system of the present invention can be used tofacilitate the use of a primary fuel and an alternate fuel in aninternal combustion engine. The present invention can be simple andinexpensive, and in some cases, can be easily adaptable to vehiclesdesigned to operate using a primary fuel. Thus, the present inventioncan be used to convert such an engine to one that is capable of usingboth a primary fuel source and an alternate fuel source.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S)

Having thus described the invention in general terms, reference will nowbe made to the accompanying drawings, which are not necessarily drawn toscale, and wherein:

FIG. 1 is a schematic illustration of a fuel control system inaccordance with one embodiment of the present invention;

FIG. 2 is a schematic illustration of a two-valve embodiment of the fuelcontrol system in accordance with another embodiment of the presentinvention;

FIG. 3 is a schematic illustration of a fuel control system inaccordance with another embodiment of the present invention having aheating mechanism, temperature sensing devices, and volume measurementdevices;

FIG. 4 is a schematic illustration of a fuel control system inaccordance with another embodiment of the present invention;

FIG. 5 is a schematic illustration of a fuel control system inaccordance with another embodiment of the present invention having adiesel fuel flow measurement device and a vegetable oil fuel flowmeasurement device;

FIG. 6 is a schematic illustration of a fuel control system inaccordance with another embodiment of the present invention having avegetable oil fuel flow measurement device and a fuel supply measurementdevice;

FIG. 7 a schematic illustration of a fuel control system in accordancewith another embodiment of the present invention having a diesel fuelflow measurement device and a fuel supply measurement device;

FIG. 8 is a schematic illustration showing a fuel control systememploying fuel injectors in accordance with another embodiment of thepresent invention;

FIG. 9 is a schematic illustration showing a fuel control systememploying a fuel injector having a primary input port and an alternateinput port in accordance with another embodiment of the presentinvention;

FIG. 10 is a schematic illustration showing a fuel control systememploying a fuel injector having a primary input port and an alternateinput port in accordance with another embodiment of the presentinvention;

FIG. 11 is a schematic illustration showing an original fuel injectortiming pattern divided to create a primary fuel injector timing patternand an alternate fuel injector timing pattern in accordance with oneembodiment of the present invention;

FIG. 12 is a schematic illustration showing an original fuel injectortiming pattern divided to create a primary fuel injector timing patternand an alternate fuel injector timing pattern in accordance with anotherembodiment of the present invention;

FIG. 13 is a schematic illustration showing an original fuel injectortiming pattern divided to create a primary fuel injector timing patternand an alternate fuel injector timing pattern in accordance with anotherembodiment of the present invention;

FIG. 14 is a schematic illustration showing an original fuel injectortiming pattern divided to create a primary fuel injector timing patternand an alternate fuel injector timing pattern in accordance with anotherembodiment of the present invention;

FIG. 15 depicts a hardware implementation for dividing original fuelinjector timing pulses into primary and alternate fuel injection outputpulses in accordance with one embodiment of the present invention; and

FIG. 16 depicts a hardware implementation for dividing original fuelinjector pulses into primary and alternate fuel injection output pulsesin accordance with another embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

The present inventions now will be described more fully hereinafter withreference to the accompanying drawings, in which some, but not allembodiments of the inventions are shown. Indeed, these inventions may beembodied in many different forms and should not be construed as limitedto the embodiments set forth herein; rather, these embodiments areprovided so that this disclosure will satisfy applicable legalrequirements. Like numbers refer to like elements throughout.

The present invention provides a fuel control system that can generallybe used as an inexpensive and easily adaptable solution for selectivelydelivering a primary fuel and an alternate fuel for operation of anengine. For the purposes of this application, the term “selectivelydeliver,” and other forms thereof, is defined as providing an enginewith 100% primary fuel and 0% alternate fuel, 100% alternate fuel and 0%primary fuel, or any mixture of primary fuel and alternate fuel. As willbe discussed in more detail below, the selection or mixing of fuels maybe accomplished in a variety of ways and may be automated andcontinuously adaptable based on a variety of data, including datarepresentative of the vehicle, the engine, and the environment.

Referring now to the drawings and, in particular, to FIG. 1, there isshown a fuel control system 20 for use in providing fuel to an internalcombustion engine of a vehicle in accordance with one embodiment of thepresent invention. The fuel used by the engine may be a primary fuel 27contained in a first fuel source 28, an alternate fuel 29 contained in asecond fuel source 30, or, as will be described in more detail below,any combination of the primary fuel 27 and the alternate fuel 29. Thefuel control system 20 depicted in FIG. 1 also includes a valve device26, an electronic controller 32, and a global positioning system (GPS)receiver 34. For the purposes of this application, the term “valvedevice” is defined as any device capable of controlling in any way theflow of a fuel or fuels. It should be noted that in various embodiments,a valve device may or may not include a valve.

As shown in FIG. 1, the valve device 26 is configured to receive fuelfrom both the first fuel source 28 and the second fuel source 30, andgenerates a fuel supply 38 that is provided to the engine of thevehicle. The valve device 26, and hence the selection of the fuels, iscontrolled by a controller such as the electronic controller 32 oranother controlling device, such as a microprocessor. In particular, theelectronic controller 32 is structured to control the valve device 26 toselectively deliver the primary fuel 27 from the first fuel source 28and the alternate fuel 29 from the second fuel source 30 according tothe data 36 that is communicated to the electronic controller 32 fromthe GPS receiver 34.

As is commonly known in the art, the electronic controller 20 maycomprise any device or combination of devices capable of controlling thevalve device 26 such as through an algorithm, including, but not limitedto, discrete logic circuits, synchronous or asynchronous machines,programmable gate arrays, and digital circuits and/or analog circuits.Likewise, control of the valve device 26 may be accomplished in manyways as are commonly known in the art including, but not limited to,electrical current established directly by driving a solenoid thatcontrols the valve device 26, or indirect electrical control of a vacuumvalve that controls the valve device 26. It should be noted that invarious embodiments, the electronic controller 20 includes data storagememory that may be used for the basic computational functions. The datastorage memory may also be used to store other data such as vehicle typeand configuration data, user preferences, modes and settings, and togather statistical data relating the operation of the vehicle and/orengine for display or for archival for later analysis and presentation.The electronic controller 20 may also be capable of communicating toexternal devices such as laptop computers and PDAs (Personal DataAssistants).

In the depicted embodiment, the alternate fuel 29 and the primary fuel27 are provided to the valve device 26 under pressure. This can beaccomplished in a number of ways as is commonly known in the art,including, but not limited to, a suction pump or other flow inducingmechanism, or by pressurizing the fuel sources. As a result, in variousembodiments, flow may be established whenever there is no restriction inthe path to the engine. In the depicted embodiment, the valve device isarranged such that loss or failure of control from the electroniccontroller 20 will result in use of the primary fuel 27.

GPS refers to a worldwide satellite navigational system of satellitesthat orbit the earth. Currently, there are about two dozen satellites inthis system. The GPS satellites transmit uninterrupted radio signalscontaining precise information regarding each satellite's location, aswell as information that indicates the length of time the signal took toreach the GPS receiver. A GPS receiver can receive signals from anynumber of satellites. By triangulating information received from threeGPS satellites, a GPS receiver is typically capable of determining alongitude value and a latitude value that correspond the location of theGPS receiver. By using four satellites, a GPS system can typically alsodetermine an altitude value that corresponds to the location of the GPSreceiver.

Thus, by equipping a vehicle with a GPS receiver, such as the GPSreceiver 34 shown in FIG. 1, a variety of GPS data 36 may be provided tothe electronic controller 32. The GPS receiver 34 can transmit the GPSdata 36 to the electronic controller 37 via physical connections, suchas soldered connections, plug-type connections, etc., and otherconnections such as wireless connections, optical connections, etc. “GPSdata” 36 refers to any data that may be gathered, determined, orcalculated using the GPS receiver, and may include vehicle location,vehicle speed, vehicle acceleration, vehicle altitude, ground surfacegrade, and other similar data. For example, vehicle speed may relate tothe rate of change of vehicle location, vehicle acceleration may relateto the rate of change of vehicle speed, and ground surface grade mayrelate to the rate of change of the vehicle altitude. In the embodimentshown in FIG. 1, the electronic controller 32 receives the GPS data 36from the GPS receiver 34 and processes the GPS data 36 in order tocontrol the valve device 26 to selectively deliver the primary fuel 27and the alternate fuel 29 according to the GPS data 36.

The fuel system 20 is capable of automatically generating a fuel supply38 with a composition ranging from 100% primary fuel 27 and 0% alternatefuel 29 to 100% alternate fuel 29 and 0% primary fuel 27. That is, thefuel supply 38 may be either of the two fuels 27, 29 or a mixture of thetwo fuels in any proportion. The ability to provide mixtures of the twofuels allows the fuel to be optimally matched with certain operatingand/or environmental conditions. Such fuel supply compositions may bepre-determined based on optimal performance characteristics of theengine given the GPS data 36 processed by the electronic controller 32.Additionally, the ability to provide mixtures further allows for gradualtransitions in operating conditions, such as where the fuel supply 38switches from 100% primary fuel 27 to 100% alternate fuel 29 and viceversa.

It has been determined that at low temperatures, the viscosity of somealternate fuels may not be optimal for use in an engine designed to runon primary fuel. For example, an alternative fuel may not flow properlythrough a diesel engine if the fuel is below a certain temperature andtherefore too viscous. However, at higher temperatures, the viscosity ofthe alternate fuel may be such that it will easily pass through the fueldelivery system. Thus, in one embodiment, the temperature of thealternate fuel can be related to GPS data 36, and the fuel controlsystem 20 of the present invention can be used to control switchingbetween 100% primary fuel 27 and 100% alternate fuel 29 based on a datathreshold value. For example, the electronic controller 32 can determinethat the engine and/or the fuel is at a minimum temperature if thevehicle has moved a certain distance within a certain time interval, ifthe vehicle has achieved a certain speed, or according to otheroperational characteristics determined using the GPS data 36. In somecases, the performance of the engine can be affected by the compositionof the fuel supply 38 during certain vehicle conditions, and theelectronic controller 32 can selectively provide a fuel supplycomposition 38 that comprises any mixture of the two fuels 27, 29 basedon the GPS data. Thus, for example, it may be predetermined that aparticular fuel supply composition 38 having a specific ratio of primaryfuel 27 to alternate fuel 29 may be advantageous at a certain vehiclespeed (as determined by the GPS receiver), and therefore the electroniccontroller 32 may control the valve device 26 to provide the specificratio of primary fuel 27 to alternate fuel 29 when the GPS receiver 34transmits vehicle speed data corresponding to that speed. Alternatively,it may be predetermined that a particular fuel supply composition 38having a specific ratio of primary fuel 27 to alternate fuel 29 may beadvantageous at certain vehicle altitudes (as determined by the GPSreceiver 34), and therefore the electronic controller 32 of the presentinvention may control the valve device 26 to provide the specific ratioof primary fuel 27 to alternate fuel 29 when the GPS receiver 34transmits vehicle altitude data corresponding to that altitude. Itshould be noted that in various embodiments, the electronic controller32 of the present invention may also be capable of controlling the valvedevice 26 based on combinations of GPS data (such as, for example, acertain vehicle speed while the vehicle is positioned at a certainaltitude, or according to vehicle speed and a rate of change of thevehicle's altitude).

It should be noted that in other embodiments of the present invention,the single valve device 26 may be replaced by multiple valve devices.For example, FIG. 2 shows a fuel control system 20 according to anotherembodiment of the present invention in which a primary valve device 40receives primary fuel 27 contained in a first fuel source 28, and analternate valve device 42 receives alternate fuel 29 contained in asecond fuel source 30. The outputs of the primary valve device 40 andthe alternate valve device 42 are combined in a manifold 43 to createthe fuel supply 38. As with the embodiment depicted in FIG. 1, thisconfiguration is also capable of automatically generating a fuel supply38 that may comprise a range of compositions from 100% primary fuel 27and 0% alternate fuel 29 to 100% alternate fuel 29 and 0% primary fuel27, and any other mixture of primary fuel 27 and alternate fuel 29therebetween, according to the GPS data.

FIG. 3 shows another embodiment of the present invention that is similarto the embodiment shown in FIG. 1 in that the fuel control system 20includes a primary fuel 27 contained in a first fuel source 28, analternate fuel 29 contained in a second fuel source 30, a valve device26, an electronic controller 32, and a GPS receiver 34. The system 20 ofFIG. 3 also includes a heating device 44 controllable by the electroniccontroller 32, a temperature sensing device 46, and an alternate fuelvolume measurement device 48. The heating device 44 is structured toheat the alternate fuel 29 contained in the second fuel source 30, thetemperature sensing device 46 is structured to measure the temperatureof the alternate fuel 29, and the alternate fuel volume measurementdevice 48 is structured to measure the volume of the alternate fuel 29contained in the second fuel source 30. The heating device 44 may be anytype of heating device such as a resistive electrical heating element oran array of elements mounted adjacent or within the second fuel source30, or a device for routing heated engine coolant or heated air throughor proximate the second fuel source 30. The alternate fuel volumemeasurement device 48 can communicate an indication of the remainingvolume of the second fuel to the electronic controller 32 so that, ifthe source 30 is empty, the electronic controller 32 provides fuel tothe engine from the first fuel source 27. The temperature sensing device46 may also be used to effect a control system (not shown) wherebyheating is switched on and off, or otherwise modulated, such that anoptimum alternate fuel temperature range is maintained. Additionally,temperature information may be displayed to the user using an indicator(not shown).

In addition to receiving GPS data 36 transmitted by the GPS receiver 34,the electronic controller 32 also receives temperature data 47 from thetemperature measuring device 46 and volume data 49 from the alternatefuel volume measurement device 48. Additionally, the electroniccontroller receives various engine data 52 that may be provided by amultitude of independent sources, such as existing sensors and signalprocessing devices. For the purposes of the current specification andappended claims, the term “engine data” refers to any data that ischaracteristic of the engine, including, but not limited to enginetemperature, engine RPM data, fuel injection timing data, engine exhausttemperature data, engine exhaust particulate data, engine throttleposition data, transmission status data, emission control system data,ignition status data, and user preferences. Transmission status data mayrelate to such data as the particular gear that is selected at a giventime. Ignition status data may relate to whether the ignition is in an‘On’ or ‘Off’ position. Additionally, the ignition status data may warnof premature engine cutoff. The controller 32 can use the engine data indetermining an optimal fuel mixture for maximizing efficiency, improvingdrivability, improving performance of the dual fuel system, and/orminimizing emissions. The controller 32 may also use the data forvarious other reasons, such as for example, to purge the fuel deliverycomponents of the alternate fuel before stopping the engine.

As a result, the embodiment of the present invention illustrated in FIG.3 provides a fuel control system 20 that is capable of automaticallygenerating a fuel supply 38 that can have a range of compositions from100% primary fuel 27 and 0% alternate fuel 29 to 100% alternate fuel 29and 0% primary fuel 27, or a mixture of primary fuel 27 and alternatefuel 29 having any proportions of the two fuels, according to any GPSdata, alternate fuel temperature data, alternate fuel volume data,engine data, and any combinations thereof. For example, the electroniccontroller may process alternate fuel temperature data 47 to control thevalve device 38 to use alternate fuel 29 when the temperature of thealternate fuel 29 has reached a desirable level. Likewise, theelectronic controller may process alternate fuel volume data 49 toadjust the ratio of primary fuel 27 to alternate fuel 29 based on thelevel of the alternate fuel 29 remaining in the second fuel source 30.Similarly, the electronic controller may process engine RPM data toadjust the ratio of primary fuel 27 to alternate fuel 29 based on theload exerted on the engine.

FIG. 4 shows another embodiment of the present invention. The figuredepicts a fuel control system 20 that includes an electronic controller32 and a valve device 26. The valve device 26 receives a diesel fuel 27and a vegetable oil fuel 29 and is configured to generate a fuel supply38 to be delivered to an engine. As shown in the figure, the electroniccontroller is configured to receive a variety of operational data 54.The operational data may be supplied by a variety of sources, includingan interface to the vehicle's electronic control module, varioussensors, such as temperature sensors, wheel-pickup speed sensors,speedometer cable speed sensors, various timers, and/or other directsensing devices. For the purposes of the current specification andappended claims, the term “operational data” is defined as GPS data,engine data, and/or any other data representative of the engine,vehicle, and/or other environmental conditions. Operational data mayinclude, but is not limited, to the speed of the vehicle, enginetemperature, engine RPM data, fuel injection timing data, engine exhausttemperature data, engine exhaust particulate data, engine throttleposition data, transmission status data, emission control system data,altitude data, ground grade data, diesel fuel volume data, vegetable oilfuel volume data, vegetable oil fuel temperature data, user preferencedata, and time. The electronic controller 32 of the depicted embodimentis configured to control the valve device 26 so as to automaticallygenerate a fuel supply 38 having any composition of the two fuels, i.e.,100% diesel fuel 27, 100% vegetable oil fuel 29, or any mixturetherebetween, according to the operational data.

FIGS. 5, 6, and 7 show three additional embodiments of the presentinvention. The embodiment depicted in FIG. 5 is similar the embodimentdepicted in FIG. 4, but also includes a primary fuel flow meter 56 andan alternate fuel flow meter 58. The primary and alternate fuel flowmeters 56, 58 are structured to provide the electronic controller 32with primary fuel flow data 57 that is representative of the flow of theprimary fuel 27, and alternate fuel flow data 59 that is representativeof flow of the alternate fuel 29, respectively. In the depictedembodiment, the electronic controller 32 is configured to process theflow data 57, 59 to allow more precise control of the valve device 26 byproviding feedback of the instantaneous flow rates contributed by eachfuel such that the valve device 26 can be optimized during operation.

The control system illustrated in FIG. 6 is similar to the system ofFIG. 5, except that a fuel supply flow meter 60 is used in the place ofthe alternate fuel flow meter. The fuel supply flow meter 60 isstructured to provide the electronic controller 32 with fuel supply data61 that is representative of the flow of the fuel supply 38 to theengine. Thus, by using the alternate fuel flow data 59 and the fuelsupply data 61, the electronic controller may derive the primary fuelflow data algebraically. Therefore the electronic controller 32 canprocess the flow data 59, 61 to allow more precise control of the valvedevice 26 by providing feedback of the instantaneous flow ratescontributed by each fuel so that the valve device 26 may be optimizedduring operation.

The control system illustrated in FIG. 7 is similar to the system ofFIG. 6 except that a fuel supply flow meter 60 replaces the alternatefuel flow meter, and the alternate fuel flow is derived algebraicallyfrom the fuel supply data 61 and the primary fuel flow data 57. Thus theelectronic controller 32 can process the flow data 57, 60 to allow moreprecise control of the valve device 26 by providing feedback of theinstantaneous flow rates contributed by each fuel so that valve device26 can be optimized during operation.

With regard to embodiments of the present invention that include fuelflow measurement devices, the electronic controller may use the fuelflow data in various ways. For example, the alternate fuel flow data maybe used as an indication of the amount of alternate fuel use. Historicalfuel use data may also be captured and may be used to monitor the amountof alternate fuel being used during a period of time or for the life ofthe vehicle. This information may also be stored in a data storagememory and may be output to a display or a reader. Thus, a user candetect or monitor the nature of the operation of the system and theengine, e.g., to determine the amount of alternate fuel that is used orthe conditions under which the alternate fuel is being used.

FIG. 8 shows another embodiment of the present invention in which thevalve device is a fuel injector used to deliver fuel directly into anengine combustion chamber 66 having a piston 68. In the depictedembodiment, the fuel injector is a mechanism that delivers a stream of ametered quantity of fuel. As shown, the fuel control system 20 includesa first fuel injector 62 that receives primary fuel 28, and a secondfuel injector 64 that receives an alternate fuel 30. The first andsecond fuel injectors 62, 64 deliver fuel directly to a combustionchamber 66 of an engine. The first and second fuel injectors 62, 64 arecontrolled by an electronic controller (not shown) similar to thatdescribed above. The first and second fuel injectors 62, 64 may becontrolled in many ways as are commonly known in the art including, butnot limited to, electrical current established directly by driving asolenoid (not shown) that controls the injector operation. Theelectronic controller is structured to receive a variety of operationaldata, such as for example, vehicle speed data, engine RPM data, fuelinjection timing data, engine exhaust temperature data, engine exhaustparticulate data, engine throttle position data, transmission statusdata, emission control system data, altitude data, ground grade data,primary fuel volume data, alternate fuel volume data, alternate fueltemperature data, and user preference data, etc. As a result, the fuelcontrol system 20 of the depicted embodiment is capable of generatingany mixture of the two fuels in the combustion chamber 66, i.e., 100%primary fuel 27, 100% alternate fuel 29, or any mixture of primary fuel27 and alternate fuel 29 therebetween, as a function of the operationaldata received by the electronic controller 32.

FIG. 9 shows another control system that is similar to the system ofFIG. 8. In particular, the system 20 includes a first fuel injector 62that delivers fuel directly into a combustion chamber 66 having a piston68. The first fuel injector includes two input ports, i.e., a primaryfuel input port 63 and an alternate fuel input port 65. The input ports63, 65 of the first fuel injector 62 are independently controllable byan electronic controller (not shown) as similarly described above. Theelectronic controller is structured to receive operational data fromvarious inputs. So configured, the fuel control system is capable ofgenerating any mixture of the primary fuel 27 and alternate fuel 29 inthe combustion chamber 66, i.e., 100% primary fuel 27, 100% alternatefuel 29, or any other mixture of the two fuels therebetween, as afunction of the operational data received by the electronic controller32. This embodiment may be advantageous for use with engine types thatare inefficient or intolerant when 100% alternate fuel 29 is supplied tothe combustion chamber 66, as a predetermined amount of primary fuel canbe delivered to any or all of the combustion chambers 66 of the engine.

FIG. 10 shows another embodiment of the present invention similar tothat described with respect to FIG. 9. In the depicted embodiment, afuel control system is shown that includes a fuel injector 62 thatdelivers fuel directly into a combustion chamber 66 having a piston 68.The fuel injector 62 includes two discrete and separate flow paths. Oneflow path originates at a primary fuel input port 63 that receivesprimary fuel 27 and the other flow path originates at an alternate fuelinput port 65 that receives an alternate fuel 28. As similarly describedabove, an electronic controller is structured to receive operationaldata from various inputs. So configured, the fuel control system iscapable of generating any mixture of a primary fuel 27 and an alternatefuel 29 in the combustion chamber 66, i.e., 100% primary fuel 27, 100%alternate fuel 29, or any other mixture of the two fuels therebetween,as a function of the operational data received by the electroniccontroller.

As noted above, mixing of a primary fuel and an alternate fuel may beaccomplished in a variety of ways. FIGS. 11-14 depict several exemplaryembodiments directed to controlling the mixing of a primary fuel and analternate fuel according to an original fuel injector timing pattern. Inone embodiment, an original fuel injector timing pattern may be anexisting timing pattern designed to operate a single fuel injector. Inthe depicted embodiments, a portion of the original fuel injector timingpattern is shown as a series of original fuel injector timing pulses T1,T4, T7. As shown the figures, mixing of a primary fuel and an alternatefuel may be accomplished by dividing each original fuel injector timingpulse T1, T4, T7 into respective primary fuel injector output pulses T2,T5, T8 and alternate fuel injector output pulses T3, T6, T9. Thus, anexisting single fuel injector timing pattern may be used to generate atiming pattern for use by two fuel injectors, a primary fuel injectorand an alternate fuel injector, in order to effect mixing of a primaryfuel and an alternate fuel in accordance with the present invention. Invarious embodiments, division of each original timing pulse may bevariable and may comprise 0% to 100% of the original fuel injectortiming pulses. Thus, as shown in FIGS. 11 and 12, an original fuelinjector pulse T1 may be divided into a primary fuel injector pulse T2(which, for example, is 100% of the original fuel injector pulse T1) andan alternate fuel injector pulse T3 (which, for example, is 0% of theoriginal fuel injector pulse T1). In the depicted embodiment, subsequentprimary fuel injector timing pulses T5, T8 and alternate fuel injectiontiming pulses T6, T9, represent exemplary proportional divisions oforiginal timing pulses T4, T7. In various embodiments, the primary fuelinjector and the alternate fuel injector may be gated sequentially. Forexample, FIG. 11 shows the primary fuel injector being gated before thealternate fuel injector. However in other embodiments, the alternatefuel injector may be gated before the primary fuel injector, as shown byexample in FIG. 12. In various other embodiments, the primary fuelinjector and the alternate fuel injector may be gated non-sequentially.Additionally, various delays may be introduced. For example, FIGS. 13and 14 show embodiments in which the original fuel injector timingpulses T1, T4, T7 are divided into primary fuel injector timing pulsesT2, T5, T8 and alternate fuel injector timing pulses T3, T6, T9 that aregated non-sequentially and include delays TA, TB delaying the gating ofcertain primary and alternate fuel injector timing pulses.

FIGS. 15 and 16 depict exemplary hardware implementations for dividingoriginal fuel injector pulses into primary and alternate fuel injectionpulses. For example, FIG. 15 shows primary and alternate fuel injectors62, 64 that are chosen via a selection signal based upon an originalfuel injector pulse using two power transistors 72, 74 and an inverter78. FIG. 16 includes an electronic control unit 78 that receives theoriginal injector pulse as an input and produces the alternate andprimary fuel injector control signals. In such a configuration, theelectronic control unit possesses complete freedom to sequence theinjectors by an algorithm.

As described above, the present invention provides a fuel control systemthat facilitates use of a primary fuel and an alternate fuel in aninternal combustion engine. In one embodiment the fuel control systemincludes at least one valve device structured to deliver a fuel supplyto the engine, a first fuel source structured to provide a primary fuelto the valve device, a second fuel source structured to provide analternate fuel to the valve device, and an electronic controllerstructured to control the valve device. The electronic controller isstructured to control the valve device as a function of various data toselectively deliver the primary fuel and the alternate fuel to generatea fuel supply. In other embodiments, the fuel system may provide somemixture of the primary fuel and the alternate fuel as a function of thedata. In various embodiments, the data used to control the fuel supplycan include GPS data, engine data, environmental data, and/or otheroperational data.

Many modifications and other embodiments of the invention set forthherein will come to mind to one skilled in the art to which thisinvention pertains having the benefit of the teachings presented in theforegoing descriptions and the associated drawings. Therefore, it is tobe understood that the invention is not to be limited to the specificembodiments disclosed and that modifications and other embodiments areintended to be included within the scope of the appended claims.Although specific terms are employed herein, they are used in a genericand descriptive sense only and not for purposes of limitation.

1. A fuel control system, comprising: at least one valve deviceconfigured to direct fuel to an engine of a vehicle; a first fuel sourceconfigured to provide a primary fuel to the at least one valve device; asecond fuel source configured to provide an alternate fuel to the atleast one valve device; and an electronic controller configured tocontrol the at least one valve device to selectively direct the primaryfuel and/or the alternate fuel to the engine; wherein the electroniccontroller is further configured to control the at least one valvedevice to exclusively direct the primary fuel to the engine for a periodof time to purge the engine prior to the engine being stopped based onone or more of altitude, grade, throttle, and transmission status of thevehicle.
 2. The fuel control system of claim 1, wherein the electroniccontroller is configured to deliver a mixture of the primary fuel andthe alternate fuel to the engine.
 3. The fuel control system of claim 2,wherein the electronic controller is configured to deliver the mixtureaccording to operational data.
 4. The fuel control system of claim 3,wherein the operational data is comprised of at least one of fuelinjection timing data, engine exhaust temperature data, engine exhaustparticulate data, engine throttle position data, transmission statusdata, emission control system data, and user preferences.
 5. The fuelcontrol system of claim 1, further comprising a global positioningsystem (GPS) receiver configured to transmit GPS data to the electroniccontroller, wherein the electronic controller is further configured tocontrol the at least one valve device according to the GPS data toselectively deliver the primary fuel and/or the alternate fuel to theengine.
 6. The fuel control system of claim 1, wherein the primary fuelcomprises one of a diesel fuel or a bio-diesel fuel, and the alternatefuel comprises one of a vegetable oil fuel or a bio-diesel fuel.
 7. Thefuel control system of claim 1, further comprising a temperature sensingdevice structured to sense the temperature of the alternate fuel and/orprimary fuel.
 8. The fuel control system of claim 7, wherein theelectronic controller is further configured to heat the alternate fuelin the second fuel source based on the temperature of the alternate fueland/or primary fuel.
 9. The fuel control system of claim 7, wherein theelectronic controller is further configured to heat the primary fuel inthe first fuel source based on the temperature of the primary fueland/or alternate fuel.